Resilient support

ABSTRACT

A vibration absorbing support comprising a base having an upstanding post and a concentrically arranged flange surrounding the post with radially extending upstanding ribs therebetween. An annular elastomeric bushing is slidably fitted between the post and the flange and rests on the ribs. The bushing supports a base for a vibrating apparatus in such a manner that the elastomeric material is subjected to a shearing force in a vertical direction and a compressive force in a horizontal direction to permit a maximum amplitude of movement vertically and a restricted horizontal movement.

United States Patent 1 Busch 1 July 10, 1973 [54] RESILIENT SUPPORT584,99l 1/1947 Great Britain 248/358 R [75] Inventor: Richard E. Busch,Hacienda Heights,

Calif. Primary Examiner-J. Franklin Foss [73] Assignee: AddmasterCorporation, San Atmmey Fred Schwend Gabriel, Calif.

[22] Filed: May 15, 1972 57 ABSTRACT [2!] Appl' 253499 A vibrationabsorbing support comprising a base having an upstanding post and aconcentrically arranged [52] US. Cl. 248/22, 248/24 flange surroundingthe post with radially extending up [51] Int. Cl. 862d 23/00 standingribs therebetween. An annular elastomeric [58] Field of Search 248/22,24, 358 R, bushing is slidably fitted between the post and the 248/15,9, 21, 350; 267/ 153 flange and rests on the ribs. The bushing supportsa base for a vibrating apparatus in such a manner that the [56]References Cited elastomeric material is subjected to a shearing forcein UNlTED STATES PATENTS a vertical direction and a compressive force ina horil 587 484 6/1926 Holden 248,22 zontal direction to permit amaximum amplitude of FOREIGN PATENTS OR APPLICATIONS Flintennann 248/22movement vertically and a restricted horizontal movement.

7/1952 Germany 248/22 11 Claims, 6 Drawing Figures II x RESILIENTSUPPORT BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to resilient supports and has particular reference tomeans for supporting and absorbing the relatively low frequencyvibrations trans mitted by motor operated mechanisms, such as thosefound in business machines and the like.

2. Description of the Prior Art Business machines, such as calculators,printers, adding machines and the like, generally incorporate motordriven mechanisms of a vibratory nature. Although resilient elastomericsupports have been employed heretofore for supporting the motor drivenmechanisms of such machines most such supports maintain the elastomericmaterial under compressive stress. Since the material is largelycompressed initially by the weight of the vibratory apparatus, it maynot permit sufficient vertical movement to adequately dampen outrelatively low frequency vibrations with the result that such vibrationsmay be transmitted to the supporting surface. Although some suchsupports have been developed which utilize the shear characteristics ofthe material they are generally complicated, expensive or ineffective tocompletely dampen all vibrations transmitted thereto.

On the other hand, it is often necessary to restrict movement of theresiliently supported apparatus in a lateral or horizontal plane toprevent the same from stricking adjacent portions of the machine housingor adjacent non-vibratory parts of the apparatus which may be supportedin fixed position within the housing. For this reason, many such priormachines require special restraining or hold-down devices to be attachedto the resiliently supported mechanism during shipment to avoid damageto the parts thereof when subject to excessive shocks which are oftenincurred.

SUMMARY OF THE INVENTION According to the present invention, a simpleand inexpensive resilient support is provided, incorporating anelastomeric material which supports the vibratory device under shearstress in a vertical direction and absorbs horizontally transmittedvibrations under compressive stress. The support is compact, easy toassemble, capable of withstanding high impact shocks and provides apositive stop to limit over extension in the event of overload in adownward direction. Another stop limits excessive movement in theopposite direction.

Accordingly, a principal object of the invention is to provide animproved resilient support for a vibratory apparatus, such as the motordriven parts of a business machine.

Another object is to provide a resilient support for a vibratoryapparatus which will adequately absorb relatively low frequencyvibrations.

Another object is to provide a simple elastomeric support in which theelastomeric material is loaded under shear stress in a verticaldirection and under compressive stress in a horizontal direction.

Another object is to eliminate the need for special restraining deviceswhen shipping business machines or the like incorporating resilientlysupported motor driven apparatus.

The manner which the above and other objects of the invention areaccomplished will be readily understood LII on reference to thefollowing specification when read in conjunction of the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a'sectional plan viewillustrating part of the housing and a mounting plate for the motordriven parts of a business machine, embodying a preferred form of thepresent invention.

FIG. 2 is anenlarged sectional view of one of the vibration absorbingsupports and is taken along line 22 of FIG. 1.

FIG. 3 is a sectional plan view taken along line 3-3 of FIG. 2.

FIG. 4 is a plan view of the support boss with the elastomeric bushing,mounting plate, etc., removed.

FIG. 5 is a side view of the elastomeric bushing.

FIG. 6is a fragmentary sectional view taken substantially along thelines 6-6 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring in particular to FIG.1, the invention is illustrated as being embodied in a business machinewhich is contained in a suitable molded plastic housing, generallyindicated at 11, having a bottom or base wall 12. The latter may havesuitable supporting feet (not shown) for mounting on a supportingsurface. A plate 13 of sheet metal and carrying sapced upright walls 14is supported from the bottom wall by vibration absorbing supportsgenerally indicated at 15. The plate 13 carries a vibratory mechanism(not shown) such as a motor driven printer which may cooperate withother devices (not shown) also suitably pported by the housingindependently of the plate 13.

Referring now to FIGS. 2 to 6, each vibration absorbing support 15comprises an upstanding tubular post 16 formed integrally with thebottom wall 12 of the housing and terminating in an upper invertedconical endface 17. An annular flange 18 is also formed integral withthe bottom wall 12. The latter extends concentrically of the post 16 butterminates below the upper end thereof. Four radially extending ribs 20extend upwardly from the bottom wall 12 and terminate below the upperedge of the annular flange 18. Such ribs are triangular incross-section, as seen in FIG. 6, and each terminates in an upperrounded tip 21. Such ribs are integral with the post 16 and flange 18.

A thin walled metal cup-shaped member 22 is pressed over the upper endof the post 16 and has inwardly extending barbs 23 which, when themember 22 is forced over the post, embed into the plastic material andthus lock the member from being removed. The member 22 has an invertedconical end which is screwthreaded.

A relatively soft elastomeric bushing, generally indicated at 24, isslidably mounted on the member 22 and post 16. The bushing 24 has alarge diameter lower section 25 which is also slidable vertically withinthe upper end of the flange l8 and has a smaller diameter conical uppersection 26. An annular shoulder 27 is formed intermediate the sections25 and 26 to support the plate 13. For this purpose, the plate 13 has agenerally circular hole formed in alignment with each bushing 24. Suchopening has four spaced lands 28 forming circular edges 29 havingsubstantially the same diameter as the lower portion of the conicalsection 26 of the bushing 24. Four cut-out portions 30 are interspersedbetween the lands 28.

It will be noted that the width (a), FIG. 6, of each cut-out portion 30is considerably greater than the tip (b) of the underlying support rib20. Also, the thickness of each cut-out portion 30 is greater than theradial thickness of the annular shoulder 27 of the bushing 24 so as toextend beyond the outer periphery of the bushing. Also, the cut-outportions 30 are so oriented on the plate 13, that when the latter istitted over the bushings 24, the cut-out portions are aligned with thetips 21 of the ribs 20 and extend equally on opposite sides thereof.

It will be further noted that the plate 13 merely rests on the variousbushings 24 and the lands 28 are the only parts of the plate 13 whichare supported by the bushings 24.

Under normal load conditions, as depicted in FIG. 6, the ribs 20 indentsomewhat into the body of the elastomeric material of the bushings 24and a small portion of such material is extended into the aligned cutoutportions 30. Thus, the elastomeric material is placed solely under shearstress by the weight of the supported apparatus which utilizes the bestvibration absorbing characteristics of the material and permits aconsiderable amplitude of movement of the plate 13 in a verticaldirection due to vertical vibrations. However, upon overloading, asmay'occur if the machine is dropped, the plate 13 will arrest againstthe upper edge of the flange 18. w

it will be noted that any horizontal vibrations imparted to the plate13, will be absorbed by the upper conical sections 26 of the bushings 24which, in this case, are placed under compressive stress, thusrestricting the plate to a relatively small amplitude of movementhorizontally to prevent parts of the vibratory apparatus supported bythe plate 13 from striking the sides of the housing or from strikingassocaited devices which may be independently supported within thehousing 11.

In order to prevent the plate 13 from being dislodged from the bushings24 in the event the machine is overturned, a retainer or snubber disc 32is mounted on top of each post 16 and is retained thereon by a clampscrew 33. The latter is of the self-threading type and is threadedthrough both the threaded portion of the cap member 22 and the interiorof the post 16. During threading, the sides of the cap member 22constrain the post 16 from being expanded radially due to possibleexcessive radial forces developed by the clamp screw 33.

The disc 32 has a downwardly extending annular lip 34 which surroundsthe upper portion of the bushing 24 and positively limits upwardmovement of the plate 13. The upper conical section 26 of the bushing 24facilitates assembly of the plate 13 over the bushing.

It will be noted that the integrally united post 16, ribs 20 andsurrounding annular flange 18 form a rigid support to resist breaking oryielding in the event the machine is dropped on its side or otherwiseviolently jarred in a horizontal direction.

Although the vibration absorbing supports 15 may be made in differentsizes and proportions, it has been found that such supports, when madein the proportions shown in the drawings and comprising bushings havingan outside diameter of approximately three quarters of an inch andformed of rubber having a hardness of approximately 40, shore, areadapted to satisfactorily support most driven business machinemechanisms and to absorb any normal vibrations therefrom.

I claim: 1. A vibration absorbing support for a vibratory devicecomprising a base, an upstanding post on said base, upstanding ribsextending radially relative to said post, an annular bushing ofelastomeric material surrounding said post and resting on said ribs, anda supporting element for said vibratory device, said supporting elementresting on said bushing and having an opening surrounding said post, theedges of said opening having portions fitting the side of said bushings,and said opening having portions located in vertical alignment withrespective ones of said ribs. 2. A vibration absorbing support accordingto claim wherein said bushing is slidable along said post. 3. Avibration absorbing support according to claim wherein said bushingcomprises a large diameter section adjacent the lower end thereof and asmall diameter section adjacent the upper end thereof, said bushinghaving an annular shoulder intermediate said sections, said openingfitting over said small diameter section and the portion of said elementsurrounding said opening resting on said annular shoulder. 4. Avibration absorbing support according to claim 1 comprising anupstanding annular flange on said base and surrounding said ribs,

said flange extending concentrically of said post and adapted to arrestsaid supporting element upon downward displacement of said supportingelement beyond a predetermined amount relative to said base. 5. Avibration absorbing support according to claim 4 wherein said ribs areintegral with said post and said annular flange.

6. A vibration absorbing support according to claim 1 comprising asnubber member on said post, said snubber member retaining said bushingon said post and engageable by said supporting element upon upwarddisplacement of said supporting element beyond a predetermined amountrelative to said base. I 7. A vibration absorbing support according toclaim 6 comprising a screw threaded axially into said post for securingsaid snubber member to the top of said post. 8. A vibration absorbingsupport according to claim 3 wherein said upper diameter section of saidbushing is conical and has its largest diameter portion adjacent saidannular shoulder.

9. A vibration absorbing support according to claim 7 wherein said baseand said post are molded of plastic, comprising an inverted cup shapedmember of metal surrounding said post, said cup shaped member beingscrew-threaded to threadably receive said screw.

10. A vibration absorbing support according to claim 9 wherein saidsupporting element comprises a horizontally extending plate of sheetmetal.

said sections,

a horizontally extending support plate for supporting said vibratorydevice,

said plate having an opening therein fitted over said small diametersection of said bushing,

a portion of said plate surrounding said opening resting on said annularshoulder, and

said opening having portions in vertical alignment with respective onesof said ribs.

III t

1. A vibration absorbing support for a vibratory device comprising abase, an upstanding post on said base, upstanding ribs extendingradially relative to said post, an annular bushing of elastomericmaterial surrounding said post and resting on said ribs, and asupporting element for said vibratory device, said supporting elementresting on said bushing and having an opening surrounding said post, theedges of said opening having portions fitting the side of said bushings,and said opening having portions located in vertical alignment withrespective ones of said ribs.
 2. A vibration absorbing support accordingto claim 1 wherein said bushing is slidable along said post.
 3. Avibration absorbing support according to claim 1 wherein said bushingcomprises a large diameter section adjacent the lower end thereof and asmall diameter section adjacent the upper end thereof, said bushinghaving an annular shoulder intermediate said sections, said openingfittiNg over said small diameter section and the portion of said elementsurrounding said opening resting on said annular shoulder.
 4. Avibration absorbing support according to claim 1 comprising anupstanding annular flange on said base and surrounding said ribs, saidflange extending concentrically of said post and adapted to arrest saidsupporting element upon downward displacement of said supporting elementbeyond a predetermined amount relative to said base.
 5. A vibrationabsorbing support according to claim 4 wherein said ribs are integralwith said post and said annular flange.
 6. A vibration absorbing supportaccording to claim 1 comprising a snubber member on said post, saidsnubber member retaining said bushing on said post and engageable bysaid supporting element upon upward displacement of said supportingelement beyond a predetermined amount relative to said base.
 7. Avibration absorbing support according to claim 6 comprising a screwthreaded axially into said post for securing said snubber member to thetop of said post.
 8. A vibration absorbing support according to claim 3wherein said upper diameter section of said bushing is conical and hasits largest diameter portion adjacent said annular shoulder.
 9. Avibration absorbing support according to claim 7 wherein said base andsaid post are molded of plastic, comprising an inverted cup shapedmember of metal surrounding said post, said cup shaped member beingscrew-threaded to threadably receive said screw.
 10. A vibrationabsorbing support according to claim 9 wherein said supporting elementcomprises a horizontally extending plate of sheet metal.
 11. A vibrationabsorbing support for a vibratory device comprising a base, an annularflange upstanding from said base, upstanding ribs on said base extendingradially within said flange, an annular bushing of elastomeric material,said bushing having a large diameter lower section slidable in saidflange and a small diameter upper section, said bushing having anannular shoulder intermediate said sections, a horizontally extendingsupport plate for supporting said vibratory device, said plate having anopening therein fitted over said small diameter section of said bushing,a portion of said plate surrounding said opening resting on said annularshoulder, and said opening having portions in vertical alignment withrespective ones of said ribs.